This is a prospective, single-arm, multi-center, observational, post-market registry to document the clinical safety and performance of MicroPort CardioFlow VitaFlow Liberty™ Transcatheter Aortic Valve System in the routine practice for the treatment of severe aortic valve stenosis. The primary endpoint is the composite rate of all-cause mortality and stroke with disability at 12 months.

Patients will receive transcatheter aortic valve replacement and examinations at the screening, procedure, discharge, and follow-up per local standard of care.

Inclusion Criteria:

1. Subjects of age≥ 18 years
2. Subjects with severe, symptomatic, calcific aortic stenosis who are considered at high risk for surgical aortic valve replacement (AVR).
3. Subject can understand the purpose of the clinical investigation, has signed voluntarily the informed consent form and is agreeing to the scheduled follow up requirements.

Exclusion Criteria:

1. Pre-existing mechanical heart valve in aortic position
2. A known hypersensitivity or contraindication to all anticoagulation /antiplatelet regimens (or inability to be anticoagulated for the index procedure), to nickel or titanium, to nitinol, to dairy products, to polyethylene terephthalate (PET) or contrast media
3. Ongoing sepsis, including active endocarditis
4. Anatomically not suitable for the VitaFlow Liberty TAV system
5. LVEF<20%
6. Estimated life expectancy of less than 12 months
7. Any medical, social or psychological condition that in the opinion of the Heart Team precludes the subject from receiving transcatheter aortic valve replacement
8. Currently participating in another drug or device trial (excluding registries) for which the primary endpoint has not been assessed
9. Inability to comply with the clinical investigation follow-up or other clinical investigation requirements
10. Patients temporally unable to provide written informed consent (e. g. unconscious emergency patients)

Patients with symptomatic, severe calcified aortic stenosis who are at high surgical risk.